Case for Impulse - Analysis of Conventional Structures Subjected to Blast Loads

摘要

Buildings designed for conventional loads (wind, snow, live) often have limited capacity to resist blast loads. Understanding the performance of these conventional structures when subjected to accidental explosions is important for determining protection of personnel and equipment. A variety of references provide estimates of performance for conventional structures at selected overpressure levels. Unfortunately, peak blast pressure alone is not sufficient to determine performance in most cases. Blast load duration is equally important when considering structural response. Load duration along with peak pressure defines the blast impulse. Peak pressure and impulse are both important and necessary to determine structural response and hazards produced by both structural and nonstructural components of a building. Peak pressure level tables are widely used, primarily because much of the available data was developed from nuclear weapons effects testing with very long duration loads. Additionally, overpressure is a parameter that most people have an innate understanding of whereas impulse is a parameter that is initially much harder to relate to damage effects This paper examines the response of building components to both pressure and impulse, identifies the importance of each parameter, and explores situations in which impulse controls response and debris hazards. It is intended to provide a greater understanding of the importance of impulse for persons who do not have a structural dynamics background.